Beamforming is a promising technique considered for modern mobile communication systems. Beamforming is employed for transmission employing an antenna array that comprises a plurality of antennas. By appropriately setting antenna weights that define a contribution of each one of the antennas of the antenna array to the transmission of a signal, it becomes possible to shape the sensitivity of the transmission to particularly high value in a specific beamformed direction (directive beam). By employing different antenna weights, different beam patterns can be achieved, e.g., different directive beams can be sequentially employed.
Generally, beamforming can be employed by an access node of a wireless network and/or by a communication device (UE) of the wireless network. Where beamforming is employed by a UE that is moving, it may be required to dynamically adapt the antenna weights to compensate for the movement of the UE (dynamic beamforming).
Generally, beamforming can be employed when sending and/or receiving a signal. Beamforming when sending a signal may allow directing the signal towards a receiver of interest during sending; likewise, beamforming when receiving a signal may allow providing a high sensitivity in receiving the signal originating from a transceiver of interest.
Generally, beamforming may allow for better link budgets due to lower required sending signal powers and higher received signal power; this is because transmission power can be anisotropically focused, e.g., into a solid angle of interest, if compared to a conventional scenario not employing beamforming and relying on more or less isotropic transmission.
Not all types of signals are suitable alike for being transmitted employing directive beams. Certain signals such as control signals intend to cover a comparably large surrounding of the UE. This may be a typical scenario with a specific location of the transceiver of interest is unknown or only known at a comparably high uncertainty. For such scenarios, different techniques are known. One technique is to employ so-called beam sweeping where a certain solid angle of the entire surrounding of the UE is “painted” or scanned by sweeping one or several directive beams over the area. A further scenario relies on an omni-directional pattern by means of the appropriate selection of antenna weights or by means of a separate omni-directional antenna. In such scenarios, the potentially high link budget offered by employing beamforming is traded for large area coverage.
In particular, such techniques as explained above face certain drawbacks and restrictions. Typically, where beam sweeping is employed by blindly pointing directive beams, e.g., in an arbitrary order, to discover a transceiver of interest, a time required to successfully discover the transceiver of interest and, therefore, an energy consumption to successfully discover the transceiver of interest can be high. Further, an occupation of the spectrum can be comparably high on average in such scenarios.